Java AbstractList is an abstract class that implements the Java List interface and provides skeletal implementations of most of the methods in the List interface. It is typically extended by other classes that provide concrete implementations for specific types of lists, such as Java ArrayList or Java LinkedList. Introduced in Java 1997 with Java 1.2, AbstractList provides a convenient base class for developers who need to implement custom list behaviors while inheriting basic list functionality.

https://docs.oracle.com/javase/8/docs/api/java/util/AbstractList.html